Create a new GitOps.PullRequestIssueManagement policy in the PowerShell/PowerShell repository to automatically add backport consideration labels when the CL-BuildPackaging label is added to an open pull request targeting the master branch.

Requirements:

• Add a new YAML policy file under .github/policies/.
• Policy trigger/conditions:
  • payloadType: Pull_Request
  • PR is open (isOpen)
  • labelAdded where label is CL-BuildPackaging
  • PR targets branch master using the targetsBranch condition:

    - targetsBranch:
        branch: master

• Policy actions:
  • Add labels:
    • BackPort-7.4.x-Consider
    • BackPort-7.5.x-Consider
    • BackPort-7.6.x-Consider
  • Include "not guards" so each label is only added if it is not already present.
  • Use the correct predicate name for checking if a label already exists in this policy engine. Search existing policies in this repo under .github/policies/ (and/or other configs) to find the canonical pattern (e.g., labelExists, hasLabel, etc.) and match it.

Implementation notes:

• Mirror the structure and formatting style of the existing policy file:
  • Existing reference: https://github.com/PowerShell/PowerShell/blob/master/.github/policies/labelAdded.approvedLowRisk.yml
• Pick an appropriate file name and unique id (e.g., labelAdded.clBuildPackaging.addBackportConsider).

Deliverables:

• A PR against the master branch adding the new policy file.
• Ensure YAML formatting and indentation are consistent with repo conventions.